- Merge physmem_pgt and ident_pgt, removing physmem_pgt. The merge
is broken as soon as mm/init.c:init_memory_mapping is run.
- As physmem_pgt is gone don't export it in pgtable.h.
- Use defines from pgtable.h for page permissions.
- Fix the physical memory identity mapping so it is at the correct
address.
- Remove the physical memory mapping from wakeup_level4_pgt it
is at the wrong address so we can't possibly be usinging it.
- Simply NEXT_PAGE the work to calculate the phys_ alias
of the labels was very cool. Unfortuantely it was a brittle
special purpose hack that makes maitenance more difficult.
Instead just use label - __START_KERNEL_map like we do
everywhere else in assembly.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Early in the boot process we need the ability to set
up temporary mappings, before our normal mechanisms are
initialized. Currently this is used to map pages that
are part of the page tables we are building and pages
during the dmi scan.
The core problem is that we are using the user portion of
the page tables to implement this. Which means that while
this mechanism is active we cannot catch NULL pointer dereferences
and we deviate from the normal ways of handling things.
In this patch I modify early_ioremap to map pages into
the kernel portion of address space, roughly where
we will later put modules, and I make the discovery of
which addresses we can use dynamic which removes all
kinds of static limits and remove the dependencies
on implementation details between different parts of the code.
Now alloc_low_page() and unmap_low_page() use
early_iomap() and early_iounmap() to allocate/map and
unmap a page.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
The dma_ops structure can be const since it never changes
after boot.
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Hello,
This patch against 2.6.20-git14 makes the NMI watchdog use PERFSEL1/PERFCTR1
instead of PERFSEL0/PERFCTR0 on processors supporting Intel architectural
perfmon, such as Intel Core 2. Although all PMU events can work on
both counters, the Precise Event-Based Sampling (PEBS) requires that the
event be in PERFCTR0 to work correctly (see section 18.14.4.1 in the
IA32 SDM Vol 3b). This versions has 3 chunks compared to previous where
we had missed on check.
Changelog:
- make the x86-64 NMI watchdog use PERFSEL1/PERFCTR1 instead of PERFSEL0/PERFCTR0
on processors supporting the Intel architectural perfmon (e.g. Core 2 Duo).
This allows PEBS to work when the NMI watchdog is active.
signed-off-by: stephane eranian <eranian@hpl.hp.com>
Signed-off-by: Andi Kleen <ak@suse.de>
a userspace fault or a kernelspace fault which will result in the
immediate death of the process. They should not be filled in as a
result of a kernelspace fault which can be fixed up.
Otherwise, if the process is handling SIGSEGV and examining the fault
information, this can result in the kernel space fault trashing the
previously stored fault information if it arrives between the
userspace fault happening and the SIGSEGV being delivered to the process.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Acked-by: Jan Beulich <jbeulich@novell.com>
--
arch/i386/kernel/traps.c | 24 ++++++++++++++++++------
arch/x86_64/kernel/traps.c | 30 +++++++++++++++++++++++-------
2 files changed, 41 insertions(+), 13 deletions(-)
Synchronize i386's smp_send_stop() with x86-64's in only try-locking
the call lock to prevent deadlocks when called from panic().
In both version, disable interrupts before clearing the CPU off the
online map to eliminate races with IRQ handlers inspecting this map.
Also in both versions, save/restore interrupts rather than disabling/
enabling them.
On x86-64, eliminate one function used here by folding it into its
single caller, convert to static, and rename for consistency with i386
(lkcd may like this).
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Avoid including asm/vsyscall32.h in virtually every source file.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Move inclusion of asm/fixmap.h to where it is really used rather than
where it may have been used long ago (requires a few other adjustments
to includes due to previous implicit dependencies).
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Remove clustered APIC mode. There's little point in the use of clustered APIC
mode, broadcasting is limited to within the cluster only, and chipsets have
bugs in this area as well. So default to physical APIC mode when the CPU
count is large, and default to logical APIC mode when the CPU count is 8 or
smaller.
(this patch only removes the use of genapic_cluster and cleans up the
resulting genapic.c file - removal of all remaining traces of clustered
mode will be done by another patch.)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: "Li, Shaohua" <shaohua.li@intel.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Fix a couple of inconsistencies/problems I found while reviewing the x86_64
genapic code (when I was chasing mysterious eth0 timeouts that would only
trigger if CPU_HOTPLUG is enabled):
- AMD systems defaulted to the slower flat-physical mode instead
of the flat-logical mode. The only restriction on AMD systems
is that they should not use clustered APIC mode.
- removed the CPU hotplug hacks, switching the default for small
systems back from phys-flat to logical-flat. The switching to logical
flat mode on small systems fixed sporadic ethernet driver timeouts i
was getting on a dual-core Athlon64 system:
NETDEV WATCHDOG: eth0: transmit timed out
eth0: Transmit timeout, status 0c 0005 c07f media 80.
eth0: Tx queue start entry 32 dirty entry 28.
eth0: Tx descriptor 0 is 0008a04a. (queue head)
eth0: Tx descriptor 1 is 0008a04a.
eth0: Tx descriptor 2 is 0008a04a.
eth0: Tx descriptor 3 is 0008a04a.
eth0: link up, 100Mbps, full-duplex, lpa 0xC5E1
- The use of '<= 8' was a bug by itself (the valid APIC ids
for logical flat mode go from 0 to 7, not 0 to 8). The new logic
is to use logical flat mode on both AMD and Intel systems, and
to only switch to physical mode when logical mode cannot be used.
If CPU hotplug is racy wrt. APIC shutdown then CPU hotplug needs
fixing, not the whole IRQ system be made inconsistent and slowed
down.
- minor cleanups: simplified some code constructs
build & booted on a couple of AMD and Intel SMP systems.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: "Li, Shaohua" <shaohua.li@intel.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Both old-IDE and libata should be able handle all controllers and
devices found using normal resource reservation methods.
This eliminates the awful, low-performing split-driver configuration
where old-IDE drove the PATA portion of a PCI device, in PIO-only mode,
and libata drove the SATA portion of the /same/ PCI device, in DMA mode.
Typically vendors would ship SATA hard drive / PATA optical
configuration, which would lend itself to slow (PIO-only) CD-ROM
performance.
For Intel users running in combined mode, it is now wholly dependent on
your driver choice (potentially link order, if you compile both drivers
in) whether old-IDE or libata will drive your hardware.
In either case, you will get full performance from both SATA and PATA
ports now, without having to pass a kernel command line parameter.
Signed-off-by: Jeff Garzik <jeff@garzik.org>
change_page_attr on x86-64 only flushed the TLB for pages that got
reverted. That's not correct: it has to be flushed in all cases.
This bug was added in some earlier changes.
Just flush all pages for now.
This could be done more efficiently, but for this late in the release
this seem to be the best fix.
Pointed out by Jan Beulich
Signed-off-by: Andi Kleen <ak@suse.de>
This patches fixes the silent data corruption problems being seen using the
GART iommu where 4kB of data where incorrect (seen mostly on Nvidia CK804
systems). This fix, to mark the memory regin the GART PTEs reside on as
uncacheable, also brings the code in line with the AGP specification.
Signed-off-by: Joachim Deguara <joachim.deguara@amd.com>
Signed-off-by: Andi Kleen <ak@suse.de>
* master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6:
[BRIDGE]: Unaligned access when comparing ethernet addresses
[SCTP]: Unmap v4mapped addresses during SCTP_BINDX_REM_ADDR operation.
[SCTP]: Fix assertion (!atomic_read(&sk->sk_rmem_alloc)) failed message
[NET]: Set a separate lockdep class for neighbour table's proxy_queue
[NET]: Fix UDP checksum issue in net poll mode.
[KEY]: Fix conversion between IPSEC_MODE_xxx and XFRM_MODE_xxx.
[NET]: Get rid of alloc_skb_from_cache
Since this was added originally for Xen, and Xen has recently (~2.6.18)
stopped using this function, we can safely get rid of it. Good timing
too since this function has started to bit rot.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
cache_k8_northbridges() is storing config values to incorrect locations
(in flush_words) and also its overflowing beyond the allocation, causing
slab verification failures.
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
While reviewing this code again I found a potential overflow of the bitmap.
The p4 oprofile can theoretically set bits beyond the reservation bitmap for
specific configurations. Avoid that by sizing the bitmaps properly.
Signed-off-by: Andi Kleen <ak@suse.de>
Due to an over aggressive optimizer gcc 4.2 cannot optimize away _proxy_pda
in all cases (counter intuitive, but true). This breaks loading of some
modules.
The earlier workaround to just export a dummy symbol didn't work unfortunately
because the module code ignores exports with 0 value.
Make it 1 instead.
Signed-off-by: Andi Kleen <ak@suse.de>
Provide a failsafe mechanism to avoid kernel spinning forever at
read_hpet_tsc during early kernel bootup.
This failsafe mechanism was originally introduced in commit
2f7a2a79c3, but looks like the hpet split
from time.c lost it again.
This reintroduces the failsafe mechanism
Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: Shai Fultheim <shai@scalex86.org>
Cc: Jack Steiner <steiner@sgi.com>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.text:nvidia_bugs from .data between 'early_qrk' (at offset 0x8428) and 'enable_cpu_hotplug'
WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.text:via_bugs from .data between 'early_qrk' (at offset 0x8438) and 'enable_cpu_hotplug'
WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.text:ati_bugs from .data between 'early_qrk' (at offset 0x8448) and 'enable_cpu_hotplug'
The compiler is putting it into .data because the __initdata is in the wrong
place.
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
VBE1.2 doesn't support function 15h (DDC) resulting in a 'hang' whilst
uncompressing kernel with some video cards. Make sure we check VBE version
before fiddling around with DDC.
http://bugzilla.kernel.org/show_bug.cgi?id=1458
Opened: 2003-10-30 09:12 Last update: 2007-02-13 22:03
Much thanks to Tobias Hain for help in testing and investigating the bug.
Tested on;
i386, Chips & Technologies 65548 VESA VBE 1.2
CONFIG_VIDEO_SELECT=Y
CONFIG_FIRMWARE_EDID=Y
Untested on x86_64.
Signed-off-by: Zwane Mwaikambo <zwane@infradead.org>
Signed-off-by: Andi Kleen <ak@suse.de>
The MSR reservation is per CPU and oprofile would only allocate them
on the CPU it was initialized on. Change this to handle all CPUs.
This also fixes a warning about unprotected use of smp_processor_id()
in preemptible kernels.
Signed-off-by: Andi Kleen <ak@suse.de>
This reverts commit 94985134b7 and
insteads removes the WARN_ON() that caused that commit in the first
place.
The problem is that we call disable_nonboot_cpus() in swsusp before
powering down the system in order to avoid triggering the WARN_ON()
in arch/x86_64/kernel/acpi/sleep.c:init_low_mapping() and this doesn't
work well on Thomas' system.
So instead, remove the WARN_ON() in arch/x86_64/kernel/acpi/sleep.c:
init_low_mapping(), which triggers every time during the suspend to disk
in the platform mode, as the potential problem it is related to doesn't
seem to occur in practice.
[ I think we might want to disallow the case of multiple users of that
mm, or something. Normally, playing with the current process page
tables on the current CPU should be fine as long as we don't have
other threads using those tables at the same time..
Anyway, not pretty, but better than the warning or the lockup - Linus ]
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ray Lee reported, that on an UP kernel with "noapic" command line option
set, the box locks hard during boot.
Adding some debug printks revealed, that the last action on the box
before stalling was "Send IPI" - a debug printk which was put into
smp_send_timer_broadcast_ipi().
It seems that send_IPI_mask(mask, LOCAL_TIMER_VECTOR) fails when
"noapic" is set on the command line on an UP kernel.
Aside of that it does not make much sense to trigger an interrupt
instead of calling the function directly on the CPU which gets the
PIT/HPET interrupt in case of broadcasting.
Reported-by: Ray Lee <ray-lk@madrabbit.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ray Lee <ray-lk@madrabbit.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Needed for any architecture that claims ARCH_APICTIMER_STOPS_ON_C3,
not just i386.
I'm hoping Thomas will clean this up a bit later..
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix atomicity of TIF update in flush_thread() for x86_64
Race :
parent process executing :
sys_ptrace()
(lock_kernel())
(ptrace_get_task_struct(pid))
arch_ptrace()
ptrace_detach()
ptrace_disable(child);
clear_singlestep(child);
clear_tsk_thread_flag(child, TIF_SINGLESTEP);
(which clears the TIF_SINGLESTEP flag atomically from a different
process)
(put_task_struct(child))
(unlock_kernel())
And at the same time, in the child process :
sys_execve()
do_execve()
search_binary_handler()
load_elf_binary()
flush_old_exec()
flush_thread()
doing a non-atomic thread flag update
Signed-off-by: Rebecca Schultz <rschultz@google.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Acked-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
CONFIG_CPU_FREQ=y
CONFIG_CPU_FREQ_TABLE=m
CONFIG_X86_P4_CLOCKMOD=y
arch/x86_64/kernel/built-in.o: In function `cpufreq_p4_verify':p4-clockmod.c:(.text.cpufreq_p4_verify+0x8): undefined reference to `cpufreq_frequency_table_verify'
arch/x86_64/kernel/built-in.o: In function `cpufreq_p4_cpu_exit':p4-clockmod.c:(.text.cpufreq_p4_cpu_exit+0x8): undefined reference to `cpufreq_frequency_table_put_attr'
arch/x86_64/kernel/built-in.o: In function `cpufreq_p4_cpu_init':p4-clockmod.c:(.text.cpufreq_p4_cpu_init+0x13b): undefined reference to `cpufreq_frequency_table_get_attr'
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: Dave Jones <davej@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The symbol is not actually used, but the compiler unforunately generates
a (unused) reference to it. This can happen even in modules. So export it.
Signed-off-by: Andi Kleen <ak@suse.de>
Fix the following section mismatch warnings on x86_64:
(build using defconfig)
WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.text:mtrr_bp_init from .text between 'identify_cpu' (at offset 0x65eb) and 'IRQ0x20_interrupt'
WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.data: from .text between 'finish_e820_parsing' (at offset 0x7dc2) and 'early_panic'
WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.text:e820_print_map from .text between 'finish_e820_parsing' (at offset 0x7de1) and 'early_panic'
WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.data:num_processors from .text between 'acpi_unmap_lsapic' (at offset 0xc88f) and 'acpi_register_ioapic'
WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.data:disabled_cpus from .text between 'MP_processor_info' (at offset 0x11f35) and 'mp_register_lapic'
WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.data:num_processors from .text between 'MP_processor_info' (at offset 0x11f6e) and 'mp_register_lapic'
WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.data:num_processors from .text between 'MP_processor_info' (at offset 0x11f93) and 'mp_register_lapic'
WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.data:fix_aperture from .text between 'gart_parse_options' (at offset 0x15517) and 'iommu_full'
WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.data:fix_aperture from .text between 'gart_parse_options' (at offset 0x1552c) and 'iommu_full'
WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.data:iommu_aperture_allowed from .text between 'gart_parse_options' (at offset 0x1553d) and 'iommu_full'
WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.data:iommu_aperture_allowed from .text between 'gart_parse_options' (at offset 0x15552) and 'iommu_full'
WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.data:iommu_aperture_allowed from .text between 'gart_parse_options' (at offset 0x15561) and 'iommu_full'
WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.data:iommu_aperture_allowed from .text between 'gart_parse_options' (at offset 0x15577) and 'iommu_full'
WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.data:fallback_aper_force from .text between 'gart_parse_options' (at offset 0x1558a) and 'iommu_full'
WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.data:fallback_aper_order from .text between 'gart_parse_options' (at offset 0x155bf) and 'iommu_full'
WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.data:timer_over_8254 from .text between 'ati_bugs' (at offset 0x16344) and 'via_bugs'
WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.data:timer_over_8254 from .text between 'ati_bugs' (at offset 0x16356) and 'via_bugs'
WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.data:iommu_aperture_allowed from .text between 'via_bugs' (at offset 0x16380) and 'nvidia_bugs'
WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.data:iommu_aperture_disabled from .text between 'via_bugs' (at offset 0x16397) and 'nvidia_bugs'
WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.data:acpi_use_timer_override from .text between 'nvidia_bugs' (at offset 0x163a7) and 'arch_unregister_cpu'
WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.text:nvidia_hpet_check from .text between 'nvidia_bugs' (at offset 0x163b1) and 'arch_unregister_cpu'
WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.data: from .text between 'nvidia_bugs' (at offset 0x163be) and 'arch_unregister_cpu'
WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.data: from .text between 'nvidia_bugs' (at offset 0x163d1) and 'arch_unregister_cpu'
WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.data:acpi_skip_timer_override from .text between 'nvidia_bugs' (at offset 0x163e1) and 'arch_unregister_cpu'
WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.text:quirk_intel_irqbalance from .text between 'intel_bugs' (at offset 0x1633c) and 'ati_bugs'
But adds:
WARNING: arch/x86_64/kernel/built-in.o - Section mismatch: reference to .init.text:get_mtrr_state from .text between 'mtrr_bp_init' (at offset 0xb887) and 'ipi_handler'
The warnings does not show up during a normal build due to kbuild
failing to check for section mismatch in vmlinux.
To see these warnings run:
scripts/mod/modpost arch/x86_64/kernel/built-in.o
kbuild will be fixed but the 'noise-level' had to be decresed first.
There remains a few section mismatch warnigns for x86_64 for areas where I did
not feel confident.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andi Kleen <ak@suse.de>
x86_64 nvidia_bugs() broke when we bailed out on not finding the HPET.
However, the quirk works by checking for _not_ finding the HPET...
Delete the nvidia_hpet_detected flag and simply test for
not finding the HPET, which is simple to do now that
acpi_table_parse returns 1 on failure.
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Also PTRACE_OLDSETOPTIONS should be accepted, as done by kernel/ptrace.c
and forced by binary compatibility. UML/32bit breaks because of this -
since it is wise enough to use PTRACE_OLDSETOPTIONS to be binary compatible
with 2.4 host kernels.
Until 2.6.17 (commit f0f2d6536e) we had:
default:
return sys_ptrace(request, pid, addr, data);
Instead here we have:
case PTRACE_GET_THREAD_AREA:
case ...:
return sys_ptrace(request, pid, addr, data);
default:
return -EINVAL;
This change was a style change - when a case is added, it must be
explicitly tested this way. In this case, not enough testing was done.
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
check_tsc_sync_source() depends on being called with irqs disabled (it
checks whether the TSC is coherent across two specific CPUs). This is
incidentally true during bootup, but not during cpu hotplug __cpu_up().
This got found via smp_processor_id() debugging.
disable irqs explicitly and remove the unconditional enabling of
interrupts. Add touch_nmi_watchdog() to the cpu_online_map busy loop.
this bug is present both on i386 and on x86_64.
Reported-by: Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch resolves the issue found here:
http://bugme.osdl.org/show_bug.cgi?id=7426
The basic summary is:
Currently we register most of i386/x86_64 clocksources at module_init
time. Then we enable clocksource selection at late_initcall time. This
causes some problems for drivers that use gettimeofday for init
calibration routines (specifically the es1968 driver in this case),
where durring module_init, the only clocksource available is the low-res
jiffies clocksource. This may cause slight calibration errors, due to
the small sampling time used.
It should be noted that drivers that require fine grained time may not
function on architectures that do not have better then jiffies
resolution timekeeping (there are a few). However, this does not
discount the reasonable need for such fine-grained timekeeping at init
time.
Thus the solution here is to register clocksources earlier (ideally when
the hardware is being initialized), and then we enable clocksource
selection at fs_initcall (before device_initcall).
This patch should probably get some testing time in -mm, since
clocksource selection is one of the most important issues for correct
timekeeping, and I've only been able to test this on a few of my own
boxes.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
